JP2009203890A - Centrifugal blower - Google Patents

Abstract

In a centrifugal blower 1, a circulating flow 15 collides with a main flow 17 flowing into an impeller 6 from a suction cylinder 8 to disturb the flow in the centrifugal direction, and the blowing efficiency is lowered. The suction cylinder 8 as a countermeasure does not have excellent workability and maintainability.
A centrifugal blower 1 includes a casing 7 that surrounds an impeller 6. A suction opening 8 has a suction drum 8. A cylindrical portion 9 and a bell mouth whose inner diameter increases from the cylindrical portion 9 toward the upstream side. A shape base portion 10 and a bell mouth shape end portion 11 whose inner diameter increases from the cylindrical portion 9 toward the downstream side are divided into an impeller side and a suction opening side in the vicinity of the minimum diameter portion, and the main plate of the impeller 6 27 is composed of a central part 30 that can be removed at the center part and a main part 41 that supports one of the blades 28, so that the suction cylinder 8 can be attached to the casing 7 with the impeller 6 assembled. Thus, the effect of improving the blowing performance can be expected.
[Selection] Figure 1

Description

  The present invention relates to a centrifugal blower used for an air-conditioning blower, a ventilation blower, or the like.

  Conventionally, this type of centrifugal blower is fixed by sandwiching a plurality of blade plates in an annular shape between a disk-shaped main plate connected to the rotating shaft of an electric motor and a donut-shaped suction shroud that is concentric with the main plate and has a suction port at the center. There has been known one provided with an impeller and a suction cylinder that guides air to the suction port of the suction shroud (see, for example, Patent Document 1).

  Hereinafter, the centrifugal blower will be described with reference to FIG.

  As shown in the figure, the centrifugal blower 101 of Patent Document 1 includes an impeller 103 including a suction shroud 102, a conical suction cylinder 104 that is tapered toward the impeller 103, and a suction cylinder concentric with the suction cylinder 104. A cylindrical mouse piece 106 connected so that an end portion 105 of 104 protrudes inwardly, and the mouse piece 106 is inserted into a suction port 107 of the impeller 103 and fixed. In addition, when the mouse piece 106 and the suction port 107 come into contact with each other due to run-out of the impeller 103 or vibration due to imbalance, or foreign matter contained in the air to be blown is clogged, loss due to friction or generation of wear, The mouse piece 106 and the suction port 107 are configured to maintain a gap 108 so that destruction due to a collision does not occur.

In the above configuration, when the impeller 103 rotates, the air flowing in from the suction drum 104 due to the pressure increasing action of the impeller 103 passes through the mouth piece 106 and flows into the impeller 103 from the suction port 107 to the impeller 103 and changes its direction in the centrifugal direction. However, since a part of the air flowing out from the suction drum 104 forms a separation vortex 109 with the mouse piece 106 at the portion where the suction drum 104 protrudes inside the mouse piece 106, In order to reduce the pressure in the portion and attract the air flow, the air flowing from the suction cylinder 104 in the direction of the rotation axis is urged to smoothly change the direction in the centrifugal direction.
Japanese Patent No. 3325574

  At this time, since the pressure of the air at the suction port 107 is lower than that of the air flowing out from the impeller 103, a part of the air flowing out from the impeller 103 passes through the gap 108 between the mouth piece 106 and the suction port 107 of the impeller 103. A circulation flow 110 is formed which again flows into the suction port 107 of the impeller 103. In such a conventional centrifugal fan 101, when the circulation flow 110 ejected from the gap 108 in the direction of the rotation axis flows into the suction port 107, the suction cylinder 104 is formed. The air flow from the suction cylinder 104 collides with the air flowing in the centrifugal direction, disturbs the flow in the centrifugal direction, and reduces the blowing performance. The circulating flow 110 collides with the air flowing in from the suction cylinder 104 and flows in the centrifugal direction. Therefore, it is required to improve the air blowing efficiency. In addition, measures that can be realized in assembly are required.

  The present invention solves such a conventional problem, and the circulation flow does not disturb the flow in the centrifugal direction by colliding with the main flow flowing into the impeller from the suction drum, and the blowing efficiency can be improved. And it aims at providing the centrifugal blower characterized by the structure excellent in construction property and maintainability.

  In order to achieve the above object, the centrifugal blower of the present invention has an electric motor, a disk-shaped main plate coupled to a rotating shaft of the electric motor, and an outer shell provided with a suction opening for sucking air and a discharge opening for discharging air. A donut-shaped suction shroud concentrically with the main plate and having a suction port for sucking air in the center, an impeller formed by sandwiching a plurality of blades between the main plate and the suction shroud, and an outer suction to the suction shroud suction port A suction cylinder fixed so as to guide air from the opening for use, the downstream end of the suction cylinder is inserted into the impeller through the suction port of the suction shroud, and a gap is provided between the suction cylinder and the suction shroud. In the centrifugal blower, a part of the air that flows out of the impeller flows into the suction port from the gap between the suction drum and the suction shroud. The blow-out direction from the gap is directed to the centrifugal direction, and the suction cylinder has a throttle section, and has a coupling portion that couples the impeller side and the suction opening side in the vicinity of the minimum diameter portion, The main plate is composed of a central portion having an outer periphery larger than an outer diameter of the bell mouth shape portion, and a main portion provided further on the outer peripheral side of the central portion, with the rotation axis of the electric motor as a center. Is.

  By this means, a part of the air flowing out from the impeller can be directed to the centrifugal direction in which the circulation flow formed by flowing into the impeller suction port again through the gap between the suction cylinder and the suction shroud is blown out from the gap. , The direction in which the circulating flow blows out can flow along the main flow that flows into the impeller from the suction cylinder and flows in the centrifugal direction, and the circulating flow collides with the main flow, thereby disturbing the flow in the centrifugal direction and reducing the blowing performance. A centrifugal blower with improved workability and maintainability that allows the suction drum to be removed while the impeller is assembled can be obtained.

  According to another means, a positioning portion for connecting the central portion and the main portion is provided on at least one of the outer peripheral edge portion of the central portion and the inner peripheral edge portion of the main portion.

  In addition, the positioning portion is composed of two or more concave and convex dowels.

  Further, the positioning part is composed of a slit and two or more convex dowels.

  Further, the positioning portion is constituted by a convex ring.

  Further, the positioning portion is characterized in that a positioning plate slightly smaller than the inner diameter of the main portion is bonded to the outer peripheral edge portion of the central portion around the rotation axis of the electric motor.

  Further, as the positioning portion, a Z-shaped step is provided on the inner peripheral edge portion of the main portion or the outer peripheral edge portion of the center portion.

  In addition, a ring portion concentric with the main plate is provided on the hub at the inner peripheral edge portion of the main portion to form a positioning portion.

  By these means, a centrifugal blower with improved workability and maintainability in which the suction drum can be removed while the impeller is assembled can be obtained.

  Further, the central portion is composed of a hub and a hub mounting plate.

  The central portion is formed integrally with the hub.

  According to the present invention, the centrifugal blower can improve the blowing efficiency without colliding with the main flow flowing into the impeller from the suction cylinder and disturbing the flow in the centrifugal direction, and has excellent workability and maintainability. Can provide.

  According to a first aspect of the present invention, in order to achieve the above object, an electric motor and a disk connected to a rotating shaft of the electric motor are provided in an outer shell having a suction opening for sucking air and a discharge opening for discharging air. -Shaped main plate, a donut-shaped suction shroud that is concentric with the main plate and has a suction port for sucking air in the center, an impeller formed by sandwiching a plurality of blades between the main plate and the suction shroud, and suction suction of the suction shroud A suction cylinder fixed to guide air from the outer suction opening of the outer shell, the downstream end of the suction cylinder is inserted into the impeller from the suction opening of the suction shroud, and the suction cylinder and the suction shroud This is a centrifugal blower with a gap in between. A part of the air that flows out of the impeller flows into the suction port from the gap between the suction cylinder and the suction shroud. The blowing direction from the gap of the ring flow is directed to the centrifugal direction, and the suction cylinder has a constricted section in cross section, and a coupling portion that couples the impeller side and the suction opening side in the vicinity of the minimum diameter portion. And the main plate is composed of a central portion having an outer periphery larger than an outer diameter of the bell mouth shape portion, and a main portion provided further on the outer peripheral side of the central portion, with the rotating shaft of the electric motor as a center. It is a characteristic, and has the effect that the workability and maintainability of removing the suction drum can be improved while the impeller is assembled.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
As shown in FIG. 1 to FIG. 3, the centrifugal blower 1 includes a suction opening 2 for sucking air on a side surface and a discharge opening 3 for discharging air on another side surface, and an electric motor 4 and a rotating shaft 5 of the motor 4 are provided. An impeller 6 that is connected and blows air by rotation of the electric motor 4 and a casing 7 that surrounds the impeller 6 are provided. The suction opening 2 has a suction cylinder 8 composed of a bell mouth shape base portion 10 and a bell mouth shape end portion 11 which are divided into an upstream side and a downstream side. The suction drum 8 includes a cylindrical portion 9, a bell mouth shape base portion 10 whose inner diameter increases from the cylindrical portion 9 toward the upstream side, and a bell mouth shape end portion 11 whose inner diameter increases from the cylindrical portion 9 toward the downstream side. Since it is provided, the minimum inner diameter position is the cylindrical portion 9 of the suction cylinder 8. The downstream end 16 of the suction cylinder 8 is located inside the impeller 6, that is, closer to the impeller 6 than the upper end of the suction shroud 13 and closer to the main plate 27.

  In the above configuration, when the impeller 6 is rotated by the electric motor 4, the outside air communicating with the suction opening 2 is introduced into the impeller 6 through the suction cylinder 8 by the pressure increasing action caused by the rotation of the blade plate 28 of the impeller 6. The air blown out from the impeller 6 is discharged outside the discharge opening 3.

  At this time, since a portion of the suction cylinder 8 is inserted into the impeller 6, the air from the suction cylinder 8 is reliably introduced into the impeller 6, but the impeller is more than the air that has flowed out of the impeller 6. 6 has a lower pressure than the air at the suction port 12, a part of the air flowing out of the impeller 6 flows into the gap 14 between the suction cylinder 8 and the suction shroud 13 to form a circulating flow 15. Since the suction cylinder 8 includes the bell mouth-shaped end portion 11 whose inner diameter increases from the cylindrical portion 9 toward the downstream end 16, the downstream end 16 of the suction cylinder 8 is bent in the centrifugal direction, and the circulation flow 15 is drawn from the gap 14. The direction to blow out can be directed to the centrifugal direction, and therefore, it can be along the main flow 17, and the circulation flow 15 collides with the main flow 17 to inhibit the centrifugal flow from being disturbed and reduce the blowing performance. It is possible to improve the ventilation efficiency.

  At this time, since the suction cylinder 8 is configured to be wound inside the suction shroud 13, it is impossible to assemble the above configuration with the integrated type. Below, the structure and assembly method of the suction cylinder 8 and the impeller 6 will be described.

  As shown in FIG. 2, the main plate 27 of the impeller 6 includes a central portion 30 that can be removed at the center thereof, and a main portion 41 that supports one of the blade plates 28. The diameter of the center portion 30 is larger than the diameter of the bell mouth shape end portion 11. The central portion 30 is concentric with the main plate 27 and has a hub 29 attached to the center. The main portion 41 is provided in an annular shape on the outer periphery of the central portion 30. The inner peripheral side of the main portion 41 and the outer peripheral side of the central portion 30 are portions that serve as joints between the main portion 41 and the central portion 30 and are provided with positioning portions 20.

  In such a configuration, an assembling method will be described. First, the bell mouth shaped end portion 11 is put into the impeller 6 with the central portion 30 removed. The bell mouth shape end portion 11 is connected to the bell mouth shape base portion 10 by the coupling portion 18 of the cylindrical portion 9 from the suction opening 2. The bellmouth shaped base portion 10 and the bellmouth shaped end portion 11 have a drawing-type cross section, and are coupled in the vicinity of the minimum diameter portion by a coupling method by bonding, screwing and caulking at the coupling portion 18. Next, the central portion 30 is attached to the main portion 41, and the hub 29 attached to the central portion 30 and the rotary shaft 5 are connected.

  Thus, after assembling the suction cylinder 8 in the casing 7, the main part 41 and the central part 30 are connected by a connecting method using adhesion, screws, and caulking, so that the impeller 6 can be attached to the electric motor 4. . The centrifugal blower 1 assembled in this way can be expected to improve the air blowing performance as described above.

  As shown in FIG. 3, two or more concave and convex dowels (convex dowels 21a and concave dowels 21b) that are fitted in pairs to the main portion 41 and the center portion 30 are provided as the positioning portions 20, respectively. You may connect in the state engage | inserted in the dowel 21. FIG.

  Further, as shown in FIG. 4, as the positioning portion 20, one of the main portion 41 and the central portion 30 is provided with a slit 22a, the other is provided with two or more convex dowels 22b, and the slit 22a is provided with a convex dowel 22b at the end. You may connect in the state put together.

  Further, as shown in FIG. 5, a convex ring 23 may be provided on either the main portion 41 or the central portion 30 as the positioning portion 20. In FIG. 5, the case where the convex ring 23 is provided in the center part 30 is shown. In this case, positioning can be easily performed by connecting the outer peripheral portion of the convex ring 23 in a state where the inner peripheral portion of the main portion 41 is aligned.

  Further, as shown in FIG. 6, a donut-shaped positioning plate 24 that is concentric with the main plate 27 and slightly smaller than the inner diameter of the main portion 41 is joined to the central portion 30 so that a step is formed in the positioning portion 20. Good. In this case, positioning can be easily performed by connecting the inner peripheral end portion of the main portion 41 and the outer peripheral end portion of the positioning plate 24 together.

  Further, as shown in FIG. 7, the positioning portion 20 is molded so as to have a step 25 on the outer peripheral portion of the center portion 30, and connected to the inner peripheral end portion of the main portion 41 and the step surface of the step 25. Also good.

  Further, as shown in FIG. 8, as the positioning portion 20, a hub 29 is provided with a ring portion 26 concentric with the main plate 27, and the inner peripheral end portion of the main portion 41 and the outer peripheral end portion of the ring portion 26 are connected together. May be.

  The hub 29 may be configured as a separate part from the central portion 30. According to such a configuration, the manufacturing cost can be reduced.

  Further, the hub 29 is molded integrally with the central portion 30 to reduce the number of components and ensure the molding accuracy of the central portion 30, thereby improving the assembly accuracy of the blower.

  The present invention realizes a centrifugal blower that can improve the blowing efficiency without impinging the flow in the centrifugal direction by colliding with the main flow flowing into the impeller from the suction cylinder, and providing a centrifugal blower with good workability. It is.

The front view which shows the centrifugal air blower of Embodiment 1 of this invention. Side sectional view showing the centrifugal blower Sectional drawing which shows attachment (unevenness dowel) of the main board of the centrifugal blower Sectional drawing which shows attachment (slit and convex dowel) of the main plate of the centrifugal blower Sectional drawing which shows attachment (convex ring) of the main board of the centrifugal blower Sectional drawing which shows attachment (positioning plate) of the main board of the centrifugal blower Sectional drawing which shows attachment (step) of the main board of the centrifugal blower Sectional drawing which shows attachment (ring part integral with hub) of the main board of the centrifugal blower Side sectional view showing a conventional centrifugal blower

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Centrifugal blower 2 Suction opening 3 Discharge opening 4 Electric motor 5 Rotating shaft 6 Impeller 7 Casing 8 Suction cylinder 9 Cylindrical part 10 Bell mouth shape base part 11 Bell mouth shape end part 12 Suction port 13 Suction shroud 14 Gap 15 Circulating flow 16 Downstream End 17 Main flow 18 Coupling portion 20 Positioning portion 21a Convex dowel 21b Concave dowel 22a Slit 22b Convex dowel 23 Convex ring 24 Positioning plate 25 Step 26 Ring portion 27 Main plate 28 Blade plate 29 Hub 30 Center portion 41 Main portion

Claims (10)

A donut comprising an electric motor, a disk-shaped main plate connected to the rotating shaft of the electric motor, and a suction port for concentrating the air concentrically with the main plate in an outer shell provided with a suction opening for sucking air and a discharge opening for discharging air Suction shroud, an impeller formed by annularly sandwiching a plurality of blades between a main plate and a suction shroud, and a suction cylinder fixed to guide air from the suction opening of the outer shell to the suction port of the suction shroud A centrifugal blower in which the downstream end of the suction cylinder is inserted into the impeller through the suction port of the suction shroud, and a gap is provided between the suction cylinder and the suction shroud. Of the circulating flow that flows into the suction port from the gap between the suction cylinder and the suction shroud, the blowing direction from the gap is directed to the centrifugal direction. In addition, the suction cylinder has a throttle-shaped cross section, and has a coupling portion that couples the impeller side and the suction opening side in the vicinity of the minimum diameter portion, and the main plate is centered on the rotating shaft of the motor. And a hub mounting plate having a hub mounting plate, characterized by comprising a central portion having an outer periphery larger than the outer diameter of the bell mouth shape portion and a main portion provided further on the outer peripheral side of the central portion. 2. The centrifugal blower according to claim 1, wherein a positioning portion for connecting the central portion and the main portion is provided on at least one of the outer peripheral edge portion of the central portion and the inner peripheral edge portion of the main portion. The centrifugal blower according to claim 2, wherein the positioning portion is configured by two or more concave and convex dowels. The centrifugal blower according to claim 2, wherein the positioning unit includes a slit and two or more convex dowels. The centrifugal blower according to claim 2, wherein the positioning portion is formed by a ring having a convex hub mounting plate. The centrifugal blower according to claim 2, wherein a positioning plate slightly smaller than the inner diameter of the main portion of the hub mounting plate is bonded to the outer peripheral edge of the central portion around the rotation shaft of the electric motor. The centrifugal blower according to claim 2, wherein a Z-shaped step is provided as an inner peripheral edge portion of the main portion or an outer peripheral edge portion of the central portion as the positioning portion. The centrifugal blower according to claim 2, wherein a ring portion concentric with the main plate is provided on the inner peripheral edge portion of the main portion to form a positioning portion. The centrifugal blower according to any one of claims 1 to 8, wherein the central portion includes a hub and a hub mounting plate. The centrifugal blower according to any one of claims 1 to 8, wherein the central portion is integrally formed with the hub.

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